HELP needed for

Guys-
I'm lost in the world of digital music. My goal is to get both 2 channel and a couple of other areas of the house served with internet, subscribed music ie rhapsody, spotify along with downloaded music files. I've looked at Sonos due to the whole house aspect but it seems lacking for 2 channel. I have a Marantz Model 250 amp, Yamaha C50 preamp, Rotel RCD1072 CD, VPI scout with Benz MC and JBL 4312 monitors to give you a reference to my humble 2 channel setup. I happen to have a Mac Mini laying around that's about 10 years old if that helps. My problem is I don't know how important my pc is, what kind of hard drive to get to best serve music files, what to do about dac (looked at dacmagic plus b/c of cost)and interconnects in general. I'm on a limited budget - say 2-3K to invest and don't expect to achieve the high level of sound quality most of you are at. PS - we have plenty of Iphones/Ipads to use as controllers. I beg you guys - please do your best to give me your best practical above average equipment set up suggestions. I appreciate your much needed advice.